EP0919669B1 - Grab bucket with verticality correction - Google Patents

Description

The subject of the present invention is a drilling bucket of the type including verticality correction systems.

The drilling rigs can be used in particular to carry out excavations with significant depth. It is particularly but not exclusively the case when you want to make a wall molded in the ground. For this, we dig successively portions of trenches having the depth total desired, these trenches being subsequently filled with concrete to make the adjacent panels of the overall diaphragm wall.

We understand that, in this case, it is important that the verticality of the digging of each portion of trench is respected with great precision especially since the depth of the diaphragm wall is important. Indeed, fault to respect this verticality, we risk having molded wall panels whose connections would not be made correctly, that is to say that there would be a significant offset in the lowest zone between two adjacent panels.

We understand that such a situation is unacceptable, especially in due to the fact that the diaphragm wall thus obtained would not have the required qualities to constitute for example the wall of buried structures.

However, there are a number of situations in which the verticality of the portion of trench dug by the drilling bucket may not be respected. This may be due to imprecision of the support system and drilling rig guide. This may also be due to heterogeneities of the soil in which the trench is dug, these heterogeneities of resistance mechanical which can result in a deviation of the drilling bucket and therefore of the portion of the trench being excavated.

We can equip such drilling rigs with systems that allow periodically check the verticality of the bucket and therefore of the trench in course of realization. However, from these indications, it is necessary to be able to act on the bucket to correct these verticality errors.

Document EP-A-0 791 690 describes a drilling bucket equipped with verticality correction pads with the technical characteristics of preamble of claim 1.

An object of the present invention is to provide a drilling bucket provided with verticality correction devices which allow such corrections with greater precision than state machines the whatever the nature, that is to say the meaning, of the defects of verticality.

• des moyens de déplacement de chaque patin par rapport au châssis, chaque moyen de déplacement comprenant un dispositif supérieur de déplacement pour déplacer l'extrémité supérieure du patin selon une direction parallèle aux axes de pivotement dans un sens et dans l'autre et un dispositif inférieur de déplacement pour déplacer l'extrémité inférieure dudit patin selon une direction parallèle aux axes de pivotement dans les deux sens ; et
• des moyens pour commander séparément les dispositifs de déplacement supérieur et inférieur de chaque patin, au moins un desdits patins comportant en outre un patin auxiliaire de correction d'inclinaison apte à faire saillie hors de la face centrale du patin et des moyens pour déplacer l'extrémité supérieure et l'extrémité inférieure dudit patin auxiliaire par rapport audit patin selon une direction orthogonale auxdits axes de pivotement.

To achieve the goal, according to the invention, the drilling bucket comprising a body provided with a frame, said body being suspended by its upper part and being provided with two pockets articulated around two pivot axes parallel to one another arranged at the the lower end of the body, said body having a vertical axis, said chassis having two main faces orthogonal to the pivot axes and two lateral faces parallel to the pivot axes, said bucket further comprising means for correcting the inclination of said bucket which include; two tilting skids of the bucket, each skate comprising two wings orthogonal to the pivot axes and parallel to the vertical axis and extending substantially over the entire height of the chassis connected to a central part (48) facing the lateral faces of the chassis, each shoe having an upper end and a lower end, the distance between the two wings of a shoe being greater than the dimension of the chassis in the direction of the pivot axes; said bucket being characterized in that it also comprises:

• means for moving each shoe relative to the chassis, each movement means comprising an upper movement device for moving the upper end of the shoe in a direction parallel to the pivot axes in one direction and in the other and a lower device moving to move the lower end of said shoe in a direction parallel to the pivot axes in both directions; and
• means for separately controlling the upper and lower displacement devices of each pad, at least one of said pads further comprising an auxiliary tilt correction pad capable of projecting out of the central face of the pad and means for moving the upper end and lower end of said auxiliary shoe with respect to said shoe in a direction orthogonal to said pivot axes.

We understand that thanks to the provisions of the invention it is possible to correct verticality defects in a large number of directions. In particular because it is possible to move in the direction of the axes of pivoting of the pockets separately the upper end and the lower end of each of the two skates, it is possible to correct a very large number of vertical defects of the body of the bucket and therefore of the bucket itself.

In addition, thanks to the presence of the auxiliary shoe, it is possible to additionally correcting verticality defects by correcting the position of the body grab in a direction that is orthogonal to the pivoting direction of drilling bucket pockets.

• la figure 1 est une vue en élévation de l'ensemble de la benne de forage suspendue à l'extrémité d'une flèche ;
• les figures 2a et 2b sont des vues respectivement de dessus et en élévation qui illustrent le principe de correction de verticalité selon l'invention ;
• la figure 3 est une vue en perspective partiellement arrachée de la benne de forage équipée de ses dispositifs de correction de verticalité ;
• les figures 4a et 4b sont des vues en coupe verticale par des plans médians montrant un mode préféré de réalisation du dispositif de déplacement supérieur du patin ;
• les figures 5a et 5b sont des vues similaires à celles des figures 4a et 4b montrant les dispositifs de déplacement inférieurs ;
• les figures 6a, 6b et 6c montrent les corrections d'erreurs de verticalité que l'on peut obtenir à l'aide des patins ; et
• les figures 7a et 7b montrent les corrections de défauts de verticalité qu'on peut obtenir grâce aux patins auxiliaires de correction de verticalité.

Other characteristics and advantages of the invention will appear better on reading the following description of several embodiments of the invention given by way of non-limiting examples. The description refers to the appended figures in which:

• Figure 1 is an elevational view of the entire drilling rig suspended from the end of a boom;
• Figures 2a and 2b are views from above and in elevation respectively which illustrate the principle of verticality correction according to the invention;
• Figure 3 is a partially cutaway perspective view of the drilling rig equipped with its verticality correction devices;
• Figures 4a and 4b are views in vertical section through median planes showing a preferred embodiment of the upper displacement device of the skate;
• Figures 5a and 5b are views similar to those of Figures 4a and 4b showing the lower displacement devices;
• FIGS. 6a, 6b and 6c show the corrections of verticality errors that can be obtained using the pads; and
• FIGS. 7a and 7b show the corrections of verticality defects which can be obtained thanks to the auxiliary pads for verticality correction.

- In Figure 1, there is shown the entire drilling bucket. We finds the drilling rig itself 10 which is suspended at the end of a arrow 12 by a cable system 14. The arrow 12 is preferably mounted on a platform 16 equipped with tracks 18. As is known, in addition to the cables 14, the arrow 12 is used for guiding towards the bucket 10 of pipes or electrical conductors such as 20 for hydraulic control and electrical movements and operation of the bucket 10. The bucket 10 essentially comprises a body 22 provided with a frame 24. The end upper 26 of the chassis 24 constitutes a point of mooring of the crane cables. The lower end of the body 22 is equipped with two pockets 28 and 30 which are articulated around two parallel axes xx 'and yy' which are orthogonal to the planes of figure 1.

The body of the bucket 22 has a vertical axis in conditions of normal operation Z-Z '. To locate the position of the bucket assembly with respect to space, to this one can associate the vertical axes Z-Z ', an axis X-X 'parallel to the pivot axes x-x' and y-y 'and an axis Y-Y' in the plane of Figure 1, this axis Y-Y 'being orthogonal to the axes x-x' and y-y '. In other words, the axis X-X 'identifies the thickness of the bucket and the axis Y-Y' identifies its width.

We also see in Figure 1 that the body of the bucket 22 is equipped two position correction pads 32 and 34 which are mounted movable by relative to the chassis 24 of the body of the bucket as will be explained later. We understand now that the pads 32 and 34 are actually in contact with the wall of the trench during digging and that by changing the position of the body of bucket compared to these two skids, we can actually correct the verticality defects of the bucket making the trench.

Referring now to Figures 2a and 2b we will describe the principle of the verticality correction device according to the invention. In Figure 2a, we have schematically represented the chassis 24 of the body of the bucket which has two vertical main faces 36 and 38 which are arranged in planes Y-Z and two lateral faces 40 and 42 which are arranged in X-Z planes. The outskirts of main faces 36 and 38 as well as the side faces 40 and 42 are covered by correction pads 32 and 34 respectively. In horizontal section, each shoe 32 or 34 has a U shape. Thus, each shoe has two wings 44 and 46 arranged opposite the periphery of the main faces 36 and 38 and a portion central 48 which connects these two wings and which is opposite the lateral faces 40 and 42 of chassis 24.

Each shoe 32 and 34 is equipped with two displacement devices in the direction X-X 'arranged respectively at the upper end and at the lower end of the skate. These displacement devices are shown schematically in Figures 2a and 2b and are referenced 50 and 52. The shoe 34 is of course also equipped with two displacement devices respectively upper and lower. As will be explained later in more detail, each displacement device 50 or 52 can be ordered separately. We understand that the relative displacements of the chassis 24 relative to the pads 32 and 34 allow to correct at the upper and lower part of the body of grab the verticality errors with respect to the X, Y and Z axes.

In order to correct verticality errors in the Y-Z plane, at least one of the two pads, for example pad 32, is equipped with an auxiliary pad 56 which can be moved relative to the pad 32 itself in the Y direction. More specifically, the auxiliary shoe 56 is itself equipped with two displacement 58 and 60, respectively upper and lower. It is thus possible, by controlling the devices 58 and 60, to move the auxiliary shoe 56 by compared to shoe 32 in the Y-Z plane.

We understand that in this embodiment only the shoe 32 is equipped with the auxiliary shoe 56. However, one would not depart from the invention if the second pad 34 was also provided with an auxiliary pad identical to pad 56.

Referring now to Figures 3 to 5, we will describe a mode preferred embodiment of the verticality correction device of the bucket.

In Figure 4a, a preferred embodiment of the upper device 50 for moving the shoe 32 relative to the chassis 24 of the dumpster.

The displacement device 50 in the direction X-X 'is essentially constituted by a guide and mechanical securing shaft 60 and by a displacement cylinder 62. The guide shaft 60 has its two ends 60a and 60b which are rigidly fixed on the wings 44 and 46 of the shoe 32. The shaft 60 is slidably engaged in a socket 63 which is connected to the chassis of the body bucket by a pivot axis 64 arranged in the direction Y-Y '. Cylinder 62 which is preferably double acting allowing to define three positions to its body 66 which is integral with the chassis of the body of the bucket. The rod 68 of the jack 62 has its free end which is pivotally connected by a pin 70 engaged in the wing 44 of the skate. The rod 68 of the jack can therefore move in the direction XX '. In one direction and in the other, more precisely, the rod 68 can take a neutral position shown in Figure 4a in which the wings 44 and 46 of the skate are symmetrical with respect to the chassis of the body. We do not induce any verticality correction at the top of the skate. The stem can take a fully retracted position as shown in Figure 4b. As shows this figure, it causes a tilt to the left with respect to the axis Z-Z 'of the skate. It can finally take a fully extended position.

Referring now to Figures 5a and 5b, we will describe a mode preferred embodiment of the lower displacement device 52. This device is still constituted by a jack 71 with three positions whose body 72 is integral with the frame 24 of the body of the bucket and whose free end of the rod 74 is mounted at pivoting on the wing 44 of the shoe 32. The displacement device 52 comprises also a guide shaft 76 which is slidably mounted in a bushing 78 rigidly secured to the chassis of the body of the bucket. Shaft 76 is mounted sliding in the direction XX 'and is parallel to the axis of the rod 74 of the jack. To allow the necessary degree of freedom, the ends 76a and 76b of the shaft 76 are engaged in oblong holes 80 and 82 formed in the wings 44 and 46 of the shoe 32. Shoulders 84 and 86 formed at the ends of the shaft 76 allow the useful mechanical connection between this tree and the wings of the skate while authorizing the degree of freedom necessary in the direction Z-Z '.

In FIG. 5a, the jack 71 is shown in its neutral position and the wings of the skate are therefore symmetrical with respect to the chassis of the body of the bucket. In on the other hand, in FIG. 5b, the jack is shown in its entirely position outlet, which gives the shoe 32 an inclination relative to the axis Z-Z '.

It is also important to note that cylinders 62 and 71 of skid displacement devices 32 and 34 can be ordered independently. We understand that in this way it is possible to communicate to these two skids of relative displacements relative to the chassis of the body of skip allowing all verticality defect corrections except verticality defects in the Y-Z plane.

These latter verticality defects can be corrected using the presence of the auxiliary shoe 56 which is connected to the displacement devices upper and lower respectively of the shoe 32 by means of two rod systems visible in Figure 3. These rods were respectively referenced 84 and 86. The links are articulated at a first end on the displacement device 50 and 52 and at a second end on the shoe 56. The upper link 84 constitutes a device for upper displacement of the shoe auxiliary while the lower link 86 constitutes the displacement device inferior. To control the movements of the shoe 56, a cylinder is provided. control 88 whose free end of the rod 90 is articulated at the end of the lower link 86 and whose body 92 is pivotally mounted relative to the main skate movement device. This constitutes a deformable parallelogram. The auxiliary shoe 56 therefore makes it possible to correct the vertical defects in the Y-Z plane by translational displacement according to the Y direction of the auxiliary shoe.

FIGS. 6 a to 6 c illustrate the corrections that can be made thanks to the displacement devices 50 and 52. It is understood that if one acts in the same way on the devices 50 and 52 of the same pad, one obtains a translational effect on this side of the body of the bucket. On the contrary, if the two devices are controlled differently, one obtains an inclination with respect to the "vertical" plane YZ.

Figures 7a and 7b illustrate the correction effect produced by the skate auxiliary 56. FIG. 7a shows the auxiliary shoe 56 at rest, which does not produce no correction.

FIG. 7b shows an auxiliary shoe 56 in the extended position, which causes a translation of the body of the bucket in the direction Y-Y '.

According to an embodiment of the invention, each device for displacement of the pads 50, 52 comprises an axis 60, 76 integral with at least one wings 44, 46 of a shoe and arranged parallel to said pivot axes between said wings, a socket 63, 78 in which is slidably engaged said axis, said sleeve being integral with chassis 24 of said bucket and a cylinder 62, 71 whose body 66, 72 is integral with the chassis and whose rod 68, 74 is moves parallel to said axis, the free end of said rod being integral with a said wings.

According to another embodiment of the invention, the socket 63 of the upper displacement device 50 is made integral with the chassis by through a joint whose axis is parallel to the vertical axis of the chassis.

Claims (6)

1. A hammer grab comprising a body (22) provided with a frame (24), said body being suspended by its upper part and being provided with two scoops (28, 30) hinged about two mutually parallel pivot pins disposed at the lower end of the body, said body comprising a vertical axis, said frame exhibiting two main faces orthogonal to the pivot pins and two side faces parallel to the pivot pins, said grab additionally comprising means of correcting the inclination of said grab which comprise: two grab inclination skids (32, 34), each skid comprising two wings (44, 46) orthogonal to the pivot pins and parallel to the vertical axis and extending over substantially the entire height of the frame in connection with a central part (48) facing the side faces of the frame, each skid having an upper end and a lower end, the distance between the two wings of a skid being greater than the dimension of the frame in the direction of the pivot pins; said grab being characterised in that it also comprises:

   means of displacing each skid relative to the frame, each displacement means comprising an upper displacement device (50) for displacing the upper end of the skid in a direction parallel to the pivot pins in one and the other directions and a lower displacement device (52) for displacing the lower end of said skid in a direction parallel to the pivot pins in both directions; and

   means of separately controlling the upper and lower displacement devices of each skid, at least one of said skids (32) additionally comprising an auxiliary inclination correction skid (56) capable of projecting out of the central face (48) of the skid and means (58, 60) of displacing the upper end and the lower end of said auxiliary skid relative to said skid in a direction orthogonal to said pivot pins.
2. A hammer grab according to claim 1, characterised in that each skid displacement device (50, 52) comprises a shaft (60, 76) integral with at least one of the wings (44, 46) of a skid and disposed parallel to said pivot pins between said wings, a bush (63, 78) in which said shaft is slidingly engaged, said bush being integral with the frame (24) of said grab, and a jack (62, 71), the body (66, 72) of which is integral with the frame and whose rod (68, 74) is displaced parallel to said shaft, the free end of said rod being integral with one of said wings.
3. A hammer grab according to claim 2, characterised in that said jack (62, 71) is a double-acting jack.
4. A hammer grab according to claim 3, characterised in that said jack (62, 71) defines three stable positions.
5. A grab according to any one of claims 2 to 4, characterised in that the bush (63) of the upper displacement device (50) is connected to the frame of the grab by a pivot pin.
6. A grab according to any one of claims 1 to 5, characterised in that said auxiliary skid (56) is connected to the skid (32) through the intermediary of two links (84, 86) hinged respectively to the upper end and the lower end of the auxiliary skid.

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